Sudoku looks intimidating with its 81-cell grid and no instructions. But every Sudoku puzzle — no matter the difficulty — can be solved using a small set of logical techniques. No maths required. Just pattern recognition.
Fill a 9×9 grid with digits 1–9 so that every row, every column and every 3×3 box contains each digit exactly once. Every puzzle has exactly one solution.
Look at each number 1–9. Find where it already appears and eliminate the rows, columns and boxes where it can't go. If only one cell in a row, column or box can hold a particular digit — fill it in.
Most Easy puzzles can be solved entirely with scanning. Always start here before anything more complex.
Pick the digit that appears most often on the board. Scan where it can go in each 3×3 box. Work through all 9 digits. Repeat until nothing new can be placed, then move to the next technique.
A naked single is a cell where only one digit is possible — all 8 others are eliminated by the row, column and box constraints. Mark candidate digits lightly in the corner of each cell, then look for cells with only one candidate left.
A hidden single is a digit that can only go in one cell within a row, column or box — even though that cell might appear to have multiple candidates. Scan each unit (row, column, box) for digits that only fit one place.
This is the most important technique for Easy and Medium puzzles. If you can spot hidden singles reliably, you can complete most puzzles without guessing.
If all candidates for a digit within a box are confined to a single row or column, that digit can be eliminated from the rest of that row or column outside the box. This removes candidates and often reveals new singles.
New puzzle every day — Easy, Medium or Hard. Hint button, mistake tracking and timer.
Play Now →Using hints is fine for learning — seeing which cell to fill next teaches you the pattern. Once you've seen the same pattern 3 times with a hint, try to find it yourself. Most players go from hint-dependent to self-sufficient within a week of daily play.